Various antennas for mounting to motor vehicles have been developed. For example, "whip-type" antennas having a flexible fiberglass or Teflon rod with a helically-wound conductor for receiving radio signals have been developed. Mobile vehicle antennas often employ a flexible mounting base to allow for impact with an object. For example, U.S. Pat. No. 4,393,383 to Yamashita discloses a spring-mounted antenna including a coaxial cable and a flexible body portion surrounding the coaxial cable. Also, global positioning satellite (GPS) navigators having quadrifilar helical antennas have been developed. For example, U.S. Pat. No. 5,198,831 discloses a GPS navigator that may be vehicle mounted, and includes a tubular, quadrifilar antenna structure. Further, various window mounted or film type antennas for vehicles have been developed. Examples of such antennas are disclosed in U.S. Pat. Nos. 5,739,794; 5,714,959; 5,648,785; 5,610,619; and 5,528,314.